There is a need in the coatings industry for high strength, high modulus, chemically resistant coatings. This invention is directed toward meeting the above needs and the coatings described herein exhibit improvements in one or more specific properties of acid resistance, pencil hardness, solvent resistance, gloss, etc.
EP-A 466,359 discloses a process for preparing phenol functionalized polymers by the polymerization of 4-acetoxystyrene and copolymerization of 4-acetoxystyrene and additional vinyl comonomers such as acrylates followed by transesterification with an alcohol. The polymers are taught to be useful as photoresist components for use in combination with UV, X-ray and E-beam imaging systems. Similarly, U.S. Pat. No. 4,857,601 discloses a process for preparing copolymers of 4-acetoxystyrene and dialkyl muconates or alkyl sorbates, followed by an alcohol or aqueous treatment with acid or base to provide the final phenol functionalized polymer.
U.S. Pat. No. 5,106,651 discloses a method for preparing coatings consisting of applying a film forming composition containing an active hydrogen-containing polymer and an aminoplast curing agent to form a coated article. No phenol functionalization is disclosed and only aliphatic hydroxy and carboxylic acid active hydrogen groups are mentioned. Further, these compositions require an additional exposure to UV radiation to produce enamels having good resistance to acid etching and water spotting.
EP-A 419,088 discloses non liquid crystalline, ester phenol capped polymers and such polymers cross-linked with aminoplast curing agents to give enamel coatings. In these compositions, the phenol moiety is always linked to the polymer through an ester group prepared by reacting polymers containing aliphatic hydroxy groups with hydroxybenzoic acids. This reference teaches that the polymers may be polyesters, alkyds, acrylics, or epoxy resins.
Additional linear, high molecular weight, phenol functionalized polymers have been prepared by polymerization of hydroxystyrenes in the presence of cationic catalysts [Masao Kato, J. of Polymer Science, Part A-1, Vol. 7, 2405-2410 (1969)]. Also, hydroxystyrenes have been copolymerized with other vinyl monomers such as acrylate esters in the presence of free radical initiators to produce phenol functionalized polymers [Masao Kato, J. of Polymer Science, Part A-1, Vol. 7, 2175-2184 (1969)]. Further, phenol functionalized polymers have been produced by radical catalyzed copolymerization of 4-(acetoxymethyl) styrene and 4-(t-butyloxycarbonyloxy) styrene followed by removal of the t butyloxycarbonyl groups from the polymer (J.M.J. Frechet, et al., Macromolecules, 1991, 24, 1746-1754). Poly(4-hydroxystyrene) has also been prepared from poly(4-vinylphenyl benzyl ether) followed by cleavage of the benzyl ether groups on the polymer by hydrobromic acid (Paolo Ferruti and Angelino Fere, J. of Polymer Science, Part A1, Vol. 9, 3671-3673 (1971)).